Perhaps you should try some spelling variations:
sach doi » sach hoi, sach moi, sach dao
vu sach » vu bach, su sach, vu khach
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
vu kham » vu khanh
vu cham » va cham, tu cham, qua cham
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet
soc va » hoc va, loc va, doc va
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach doi ((nang xa) or (nang ma)) hoi. hieu ((vu cham) OR (vu kham)) soc va danh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach doi ((nang xa) OR (nang ma)) hoi. hieu ((vu cham) OR (vu kham)) soc va danh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach doi ((nang xa) or (nang ma)) hoi. hieu ((vu cham) OR (vu kham)) soc va danh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach doi ((nang xa) or (nang ma)) hoi. hieu ((vu cham) OR (vu kham)) soc va danh vi cua tre*.